Modem and connection

Saturday, December 04, 2004 at 8:23 am
Yesterday, I chatted with YenFong from 11.00a.m to 3.40p.m non-stop. We chat about something, someting and something. Then, she came into a topic, internet optimization or internet tweaking. She got a ADSL connection (Asymmetric Direct Suscriber Line) with a 1 megabit per second download speed and 386 kibobit per second (not to confused by kibobyte per second, 1 bit = 8 byte) Streamyx connection. She says that she only receives only about 300-400 kilobot per second, and guess what, i tested my connection with her, i've transferred a 4MB chunk file into hers, and guess what, the speed is 3-4KBps. What a lame. I dont know who's the snail here, neither me or her. YenFong, take note. DSL is a technology that enables high speed internet without burning your pockets. The maximum length of the cable from the pencawang to your home must less than 18,000 feet. You can use both the internet and the telephone line simultaneously. It dont uses special wire, it uses the RJ-11, that is the standard telephone wire. Every streamyx account bandwidth is set by the HOI (House Of Internet, you prick). Altough it's fast and furious, it has disadvantages. A DSL connection works better when you are closer to the provider's central office or pencawang. The connection is faster for receiving data than it is for sending data over the Internet, so it is not suitable for web servers. And, the service is not available everywhere. The RJ-11 uses copper wires. The copper wires have lots of room for carrying more than your phone conversations - they are capable of handling a much greater bandwidth, or range of frequencies, than that demanded for voice. DSL exploits this "extra capacity" to carry information on the wire without disturbing the line's ability to carry conversations. The entire plan is based on matching particular frequencies to specific tasks. To understand DSL, you first need to know a couple of things about a normal telephone line -- the kind that telephone professionals call POTS, for Plain Old Telephone Service. One of the ways that POTS makes the most of the telephone company's wires and equipment is by limiting the frequencies that the switches, telephones and other equipment will carry. Human voices, speaking in normal conversational tones, can be carried in a frequency range of 0 to 3,400 Hertz. This range of frequencies is tiny. For example, compare this to the range of most stereo speakers, which cover from roughly 20 Hertz to 20,000 Hertz. And the wires themselves have the potential to handle frequencies up to several million Hertz in most cases. The use of such a small portion of the wire's total bandwidth is historical -- remember that the telephone system has been in place, using a pair of copper wires to each home, for about a century. By limiting the frequencies carried over the lines, the telephone system can pack lots of wires into a very small space without worrying about interference between lines. Modern equipment that sends digital rather than analog data can safely use much more of the telephone line's capacity. DSL does just that. There are two competing and incompatible standards for ADSL. The official ANSI standard for ADSL is a system called discrete multitone, or DMT. According to equipment manufacturers, most of the ADSL equipment installed today uses DMT. An earlier and more easily implemented standard was the carrierless amplitude/phase (CAP) system, which was used on many of the early installations of ADSL. CAP operates by dividing the signals on the telephone line into three distinct bands: Voice conversations are carried in the 0 to 4 KHz (kilohertz) band, as they are in all POTS circuits. The upstream channel (from the user back to the server) is carried in a band between 25 and 160 KHz. The downstream channel (from the server to the user) begins at 240 KHz and goes up to a point that varies depending on a number of conditions (line length, line noise, number of users in a particular telephone company switch) but has a maximum of about 1.5 MHz (megahertz). This system, with the three channels widely separated, minimizes the possibility of interference between the channels on one line, or between the signals on different lines.



Notice the leftest (new word?). Its the voice bandwidth (1-4 KHz). The second is the upstream or the upload speed. The largest, is the download speed, which is occupying the largest frequency. A megabit account will recieve one megabit, a 386 kilobit will recieve 386 kilobit. My streamyx connection is a 386 kilobit per second. My bandwidth can be vary, from 1 KBps to 48KBps. Yes, after I tweaked the connection, i was able to bring back the true bandwidth of 386KBps (which is about 48 KBps). The are several things that blocks your connection to the fullest. First, check for spyware, adware or even trojans. They can consume a large bandwidth just to do bad things. If you dont have the appropriate software, you can use the online scanner and detector. There are several websites, such as Spyware and Adware and Trojans. If that did'nt work, try tweaking the connection by software, by using TWEAKmaster. It has loads of tools and utilities to bring your connection to the fullest. And, try to replace your computer to the your home's telephone jack or shortened the long wire from your jack to your DSL modem, just to shortened the bandwidth-eater resistant. There's several other noobs-dont-try-this-at-home things to do, such as hacking to the HOI's database, shotgun connections and many more. Evade using LANs to distribute the internet connection, instead, use WLAN.

Okay, it's for now. Do you have any topics to discuss about?.

p/s: saw the winner of ISEF on the newspaper, so mad that I'm really determined to do this project.

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